Three factors which effect the overall efficiency of a manufacturing line are the costs involved in manufacturing a particular item, a related factor, namely, the speed at which an item can be manufactured and, finally, quality. In general, the lower the cost to manufacture an item the better chance there is to make a profit on that item. Similarly, the faster a manufacturing line can make an individual item the greater the number of items that line can make in a day, a week or a year. Low cost, high speed manufacturing lines which produce low quality items, however, are to be avoided. Quality cannot be sacrificed in exchange for lower costs and/or higher speeds. Together these three factors, cost, speed and quality, can be lumped together into a single idea; efficiency. The lower the cost, faster the line and higher the quality of item produced, the more efficient the line becomes.
It is difficult, however, to operate an efficient manufacturing line if that line is involved in the manufacture of different items. Once the line is done making a first item it may be necessary to change elements of the line to prepare it so that it can make a second item. For instance, a manufacturing line usually comprises a number of processes, tools and fixtures. A particular item or part of an item may be held in one fixture as the item/part undergoes multiple tests or is fed to different tools or processes along the manufacturing line. One tool may perform welding while the others perform cleaning, soldering or painting to name just a few examples. When the line finishes making the first item, its"" fixture may need to be changed. A second, new fixture is designed to handle the second item. This process of changing fixtures may occur repeatedly as different items are made by the same manufacturing line.
Each time a fixture is changed the line must be halted temporarily to allow the first fixture to be replaced with the second one. The time it takes to change fixtures is referred to as the xe2x80x9cchangeover timexe2x80x9d. Time spent changing fixtures is time that cannot be spent making items. This lost time reduces the efficiency of the line. In addition to the time lost in changing fixtures, each fixture must be designed to hold a particular item. The design of the first fixture may not be the same as the second and vice-versa. Thus, money must be spent in designing and developing new fixtures, one fixture for each item, in order to make multiple items on a single manufacturing line.
It is believed that a single, multi-purpose fixture, which can be used to manufacture multiple items, would reduce changeover times and costs associated with the design and development of such fixtures without reducing quality. In short, it is believed that a multiple-purpose fixture will make a manufacturing line more efficient and more profitable.
Accordingly, it is an object of the present invention to provide for multi-purpose fixtures and methods which increase the efficiency of manufacturing lines.
It is another object of the present invention to provide for multi-purpose fixtures and methods capable of being used to manufacture multiple items.
Other objectives, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the invention taken in conjunction with the accompanying drawings and claims.
In accordance with the present invention there are provided multi-purpose fixtures and methods for increasing the efficiency of manufacturing lines. A fixture envisioned by the present invention comprises a movable frame, a rotatable table connected to the frame and two adjustable boundaries. Together the frame, table and boundaries are used to position an item, such as a telephone, substantially above a reference point. When the item is so positioned, tests may be made on the item being made or a tool or manufacturing process may be applied to the item being made. When a different item is to be manufactured, the frame, table and boundaries are adjusted to fit this item. There is no need to use a different fixture for each item to be manufactured.
Such a fixture can be used to design and develop items as well. A test fixture comprising a set of boundaries can be adapted to measure a sample item. The dimensions measured can then be sent to another fixture used in the manufacturing process.
The use of a fixture envisioned by the present invention reduces changeover times when different items are being made on the same manufacturing line.
The present invention and its advantages can be best understood with reference to the drawings, detailed description of the invention and claims that follow.